﻿<!DOCTYPE html>
<HTML>
<HEAD>
  <TITLE> ZTREE DEMO - big data async</TITLE>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <link rel="stylesheet" href="../../../css/demo.css" type="text/css">
  <link rel="stylesheet" href="../../../css/zTreeStyle/zTreeStyle.css" type="text/css">
  <script type="text/javascript" src="../../../js/jquery-1.4.4.min.js"></script>
  <script type="text/javascript" src="../../../js/jquery.ztree.core-3.5.js"></script>
  <script type="text/javascript" src="../../../js/jquery.ztree.excheck-3.5.js"></script>
  <script type="text/javascript" src="../../../js/jquery.ztree.exedit-3.5.js"></script>
  <SCRIPT type="text/javascript">
    <!--
    var setting = {
      async: {
        enable: true,
        url: getUrl
      },
      check: {
        enable: true
      },
      data: {
        simpleData: {
          enable: true
        }
      },
      view: {
        expandSpeed: ""
      },
      callback: {
        beforeExpand: beforeExpand,
        onAsyncSuccess: onAsyncSuccess,
        onAsyncError: onAsyncError
      }
    };

    var zNodes = [
      { name: "500个节点", id: "1", count: 500, times: 1, isParent: true },
      { name: "1000个节点", id: "2", count: 1000, times: 1, isParent: true },
      { name: "2000个节点", id: "3", count: 2000, times: 1, isParent: true }
    ];

    var log,
      className = "dark",
      startTime = 0,
      endTime = 0,
      perCount = 100,
      perTime = 100;

    function getUrl(treeId, treeNode) {
      var curCount = (treeNode.children) ? treeNode.children.length : 0;
      var getCount = (curCount + perCount) > treeNode.count ? (treeNode.count - curCount) : perCount;
      var param = "id=" + treeNode.id + "_" + (treeNode.times++) + "&count=" + getCount;
      return "../asyncData/getNodesForBigData.php?" + param;
    }

    function beforeExpand(treeId, treeNode) {
      if (!treeNode.isAjaxing) {
        startTime = new Date();
        treeNode.times = 1;
        ajaxGetNodes(treeNode, "refresh");
        return true;
      } else {
        alert("zTree 正在下载数据中，请稍后展开节点。。。");
        return false;
      }
    }

    function onAsyncSuccess(event, treeId, treeNode, msg) {
      if (!msg || msg.length == 0) {
        return;
      }
      var zTree = $.fn.zTree.getZTreeObj("treeDemo"),
        totalCount = treeNode.count;
      if (treeNode.children.length < totalCount) {
        setTimeout(function() { ajaxGetNodes(treeNode); }, perTime);
      } else {
        treeNode.icon = "";
        zTree.updateNode(treeNode);
        zTree.selectNode(treeNode.children[0]);
        endTime = new Date();
        var usedTime = (endTime.getTime() - startTime.getTime()) / 1000;
        className = (className === "dark" ? "" : "dark");
        showLog("[ " + getTime() + " ]&nbsp;&nbsp;treeNode:" + treeNode.name);
        showLog("加载完毕，共进行 " + (treeNode.times - 1) + " 次异步加载, 耗时：" + usedTime + " 秒");
      }
    }

    function onAsyncError(event, treeId, treeNode, XMLHttpRequest, textStatus, errorThrown) {
      var zTree = $.fn.zTree.getZTreeObj("treeDemo");
      alert("异步获取数据出现异常。");
      treeNode.icon = "";
      zTree.updateNode(treeNode);
    }

    function ajaxGetNodes(treeNode, reloadType) {
      var zTree = $.fn.zTree.getZTreeObj("treeDemo");
      if (reloadType == "refresh") {
        treeNode.icon = "../../../css/zTreeStyle/img/loading.gif";
        zTree.updateNode(treeNode);
      }
      zTree.reAsyncChildNodes(treeNode, reloadType, true);
    }

    function showLog(str) {
      if (!log) log = $("#log");
      log.append("<li class='" + className + "'>" + str + "</li>");
      if (log.children("li").length > 4) {
        log.get(0).removeChild(log.children("li")[0]);
      }
    }

    function getTime() {
      var now = new Date(),
        h = now.getHours(),
        m = now.getMinutes(),
        s = now.getSeconds(),
        ms = now.getMilliseconds();
      return (h + ":" + m + ":" + s + " " + ms);
    }

    $(document).ready(function() {
      $.fn.zTree.init($("#treeDemo"), setting, zNodes);

    });
    //-->
  </SCRIPT>
</HEAD>

<BODY>
<h1>分批异步加载大数据量</h1>
<h6>[ 文件路径: bigdata/diy_async.html ]</h6>
<div class="content_wrap">
  <div class="zTreeDemoBackground left">
    <ul>
      <li class="highlight_red">&nbsp;&nbsp;&nbsp;&nbsp;此 Demo 专门用于测试分批异步加载，每次展开节点都要重新进行异步加载。</li>
    </ul>
    <ul id="treeDemo" class="ztree"></ul>
  </div>
  <div class="right">
    <ul class="info">
      <li class="title">
        <h2>1、大数据量加载说明</h2>
        <ul class="list">
          <li>1)、对于某一级节点数多达几千个的时候，zTree 默认的延迟加载是无效的，此 Demo 演示了一种原先 zTree v2.6 时的分批加载节点的方法。</li>
          <li class="highlight_red">2)、此方法适用于1、2千个节点必须全部显示的需求。</li>
          <li class="highlight_red">3)、此方法并不能解决加载慢的问题，相反只会让最终结果出现的更慢，只是可以有限度的避免浏览器假死，而且显示的节点越多就越慢。</li>
          <li>
            4)、对于某一级节点数至少几千个的情况，另一个解决方案是：分页异步加载。<br/>
            async load log:<br/>
            <ul id="log" class="log" style="height: 85px"></ul>
          </li>
        </ul>
      </li>
      <li class="title">
        <h2>2、setting 配置信息说明</h2>
        <ul class="list">
          <li>需要设置 setting.async 异步加载部分的参数</li>
          <li>建议关闭动画效果 setting.view.expandSpeed = "";</li>
          <li>其他不需要进行特殊的配置，根据自己的需求自行设置</li>
        </ul>
      </li>
      <li class="title">
        <h2>3、treeNode 节点数据说明</h2>
        <ul class="list">
          <li>对 节点数据 没有特殊要求，用户可以根据自己的需求添加自定义属性</li>
        </ul>
      </li>
    </ul>
  </div>
</div>
</BODY>
</HTML>